This research shows that although brown argus butterfly species may have initially been able to respond to climate change by moving northwards, the result has been that the butterflies rely on a more specialised diet. This is worrying as more specialist species are less equipt to deal with further changes in climate.

Members of the brown argus butterfly species that moved north in response to recent climate change have evolved a narrower diet dependent on wild Geranium plants, researchers report. However, butterflies that did not move north have more diverse diets, including plants such as Rockrose that are abundant in southern parts of the UK.